How to search the CSD for complexes with common organometallic ligands

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Written by

Caroline Davies-Brooks

Posted on

December 10, 2021

Organometallic chemistry is a broad research area and searching for relevant structures in a database like the Cambridge Structural Database (CSD) can be a challenge. Here we show tips for searching for common types of organometallic complexes in the CSD.

Common ligands used in organometallic chemistry are:

  • Carbenes
  • N-heterocyclic carbenes
  • Phosphines
  • Sigma-complexes
  • Metal alkyls
  • Metal hydrides
  • Pi-complexes
  • Odd-numbered pi-systems
  • Carbon monoxide
  • Dative ligands of N, O, and S

The screenshots below show how to use CCDC’s Conquest software to search the Cambridge Structural Database for some of these organometallic complexes. The “Draw” search feature in ConQuest has very customizable search parameters; element type, number of hydrogens, charge, number of bonded atoms, cyclicity, and bond type. The screenshots depict how to combine these parameters to search for organometallic complexes. These searches are by no means exhaustive of the organometallic complexes in the CSD but hopefully cover enough of the editable parameters and functionality of the software to empower you with the knowledge to search for exactly what you’d like to find. The “Draw” search feature can be combined with element and name searches to provide an even more customisable search. 


Metal carbenes have a metal-carbon double bond.

 How to set up a search in ConQuest for transition metal metal carbene complexes, featuring tungsten carbene compound CSD Entry: OPALOJ 


N-heterocyclic carbenes (NHCs)

NHCs are commonly used to modulate the steric and electronic properties of metal complexes. In the CSD, we tend to use single bonds from the carbenic carbon to the metal centre, but it can depend on how the bonding is represented in the accompanying publication. This means the ConQuest search has a variable bond type to the transition metal centre.


How to set up a search in ConQuest for transition metal NHC complexes, featuring tetradentate NHC iron compound CSD Entry: AKUSIL 



Tertiary phosphines are used to modulate the electronic properties of the metal centre to which they are bound. They are easily sterically tuneable.   


How to set up a search in ConQuest for transition metal phosphine complexes, featuring osmium compound CSD Entry: CIDWER12


Metal alkyls

Metal alkyl complexes are central to organometallic chemistry and are particularly relevant for understanding catalytic systems. The image shows how to search for metal complexes with terminal alkyl ligands.


How to set up a search in ConQuest for metal alkyl complexes, featuring zinc alkyl complex CSD Entry: ANIYAA 


Metal hydrides

Metal hydrides are important in organometallic chemistrythey vary enormously in polarization and pKa. They may be acidic, hydridic, or both. They undergo insertion with a variety of unsaturated compounds to give stable species or reaction intermediates containing metal-carbon bonds. These complexes can provide insight into catalytic reactions as hydride insertion is often a key step. (ref The Organometallic Chemistry of the Transition Metals, Robert H. Crabtree.)  The search shows how to find metal complexes with terminal hydride ligands.


How to set up a search in ConQuest for metal hydride complexes, featuring dihydride platinum compound CSD Entry: HBUPPT02  


Carbon monoxide 

Carbon monoxide is ubiquitous in organometallic and coordination chemistry and plays a key role in many catalytic processes. (ref: Inorg. Chem. 1998, 37, 1080-1090). This search shows how to find metal complexes with terminal carbonyl ligand(s).


How to set up a search in ConQuest for metal carbonyl complexes, featuring recently published manganese compound CSD Entry: AKERAM 


Learn more

To learn more about how to use ConQuest check out the self-guided workshops for even more insight into the functionality of this powerful software.

Introduction to ConQuest  

Further Conquest workshops  


CSD (105)

CSD Database (24)

CSD System (45)

Organometallic Complexes (3)

Organometallic Ligands (3)